At low rotation speeds, which can occur for instance when the gas turbine engine is started or shut-down, or during windmilling, the movement of the blade roots within the blade retention slots can cause wear. The clearance between a blade root and its blade retention slot can cause the blade root to flop around in the blade retention slot. After many hours of this action, the mating surfaces on the blade root and the blade retention slot can wear away. This wear can have a detrimental impact on the low cycle fatigue life of the fan rotor hub and of the blades.
It is known to provide devices to bias the blades outwardly so as to reduce blade wear occuring at low rotation speeds, but known devices are often relatively complex to assemble. Room for improvements thus exists.